Deployable guard for portable magnetic resonance imaging devices

ABSTRACT

According to some aspects, an apparatus is provided comprising a deployable guard device, configured to be coupled to a portable medical imaging device, the deployable guard device further configured to, when deployed, inhibit encroachment within a physical boundary with respect to the portable medical imaging device. According to some aspects, an apparatus is provided comprising a deployable guard device, configured to be coupled to a portable magnetic resonance imaging system, the deployable guard device further configured to, when deployed, demarcate a boundary within which a magnetic field strength of a magnetic field generated by the portable magnetic resonance imaging system equals or exceeds a given threshold.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims priority under35 U.S.C. § 120 to U.S. patent application Ser. No. 16/937,835, titled“Deployable Guard For Portable Magnetic Resonance Imaging Devices”,filed on Jul. 24, 2020, which is a continuation of and claims priorityunder 35 U.S.C. § 120 to U.S. patent application Ser. No. 16/389,004,titled “Deployable Guard For Portable Magnetic Resonance ImagingDevices”, filed on Apr. 19, 2019, which claims the benefit of priorityunder 35 U.S.C. § 119 to U.S. Provisional Patent Application Ser. No.62/660,692, titled “Deployable Guard For Portable Magnetic ResonanceImaging Devices”, filed on Apr. 20, 2018, each of which is incorporatedby reference herein in its entirety.

BACKGROUND

The present disclosure relates generally to magnetic resonance imaging(MRI) devices and, more specifically, a deployable guard suitable foruse with portable MRI devices.

MRI provides an important imaging modality for numerous applications andis widely utilized in clinical and research settings to produce imagesof the inside of the human body. As a generality, MRI is based ondetecting magnetic resonance (MR) signals, which are electromagneticwaves emitted by atoms in response to state changes resulting fromapplied electromagnetic fields. For example, nuclear magnetic resonance(NMR) techniques involve detecting MR signals emitted from the nuclei ofexcited atoms upon the re-alignment or relaxation of the nuclear spin ofatoms in an object being imaged (e.g., atoms in the tissue of the humanbody). Detected MR signals may be processed to produce images, which inthe context of medical applications, allows for the investigation ofinternal structures and/or biological processes within the body fordiagnostic, therapeutic and/or research purposes.

MRI provides an attractive imaging modality for biological imaging dueto the ability to produce non-invasive images having relatively highresolution and contrast without the safety concerns of other modalities(e.g., without needing to expose the subject to ionizing radiation,e.g., x-rays, or introducing radioactive material to the body).Additionally, MRI is particularly well suited to provide soft tissuecontrast, which can be exploited to image subject matter that otherimaging modalities are incapable of satisfactorily imaging. Moreover, MRtechniques are capable of capturing information about structures and/orbiological processes that other modalities are incapable of acquiring.However, there are a number of drawbacks to MRI that, for a givenimaging application, may involve the relatively high cost of theequipment, limited availability (e.g., difficulty in gaining access toclinical MRI scanners) and/or the length of the image acquisitionprocess.

The trend in clinical MRI has been to increase the field strength of MRIscanners to improve one or more of scan time, image resolution, andimage contrast, which, in turn, continues to drive up costs. The vastmajority of installed MRI scanners operate at 1.5 or 3 tesla (T), whichrefers to the field strength of the main magnetic field B₀. A rough costestimate for a clinical MRI scanner is approximately one million dollarsper tesla, which does not factor in the substantial operation, service,and maintenance costs involved in operating such MRI scanners.

These high-field MRI systems typically require large superconductingmagnets and associated electronics to generate a strong uniform staticmagnetic field (B₀) in which an object (e.g., a patient) is imaged. Thesize of such systems is considerable with a typical high-field MRIinstallment including multiple rooms for the magnet, electronics,thermal management system, and control console areas. The size andexpense of high-field MRI systems generally limits their usage tofacilities, such as hospitals and academic research centers, which havesufficient space and resources to purchase and maintain them. The highcost and substantial space requirements of high-field MRI systemsresults in limited availability of MRI scanners. As such, there arefrequently clinical situations in which an MRI scan would be beneficial,but due to one or more of the limitations discussed above, is notpractical or is impossible, as discussed in further detail below.

A further consideration related to MRI systems of any field strength arestray magnetic fields produced outside the imaging region of the MRIsystems (also known as fringe fields), which are measured in Gauss.Depending on their strength, fringe fields may be dangerous tobystanders and may interfere with nearby electronics including medicaldevices (e.g., pacemakers) and computers (e.g., smartphones).

SUMMARY

Some embodiments include an apparatus comprising a deployable guarddevice, configured to be coupled to a portable medical imaging device,the deployable guard device further configured to, when deployed,inhibit encroachment within a physical boundary with respect to theportable medical imaging device.

In some embodiments, the portable medical imaging device comprises amagnetic resonance imaging (MRI) device, and the physical boundarycorresponds to a volume that encompasses a region having a definedmagnetic field strength. In some embodiments, the deployable guarddevice comprises an extendible rail. In some embodiments, the extendiblerail has a first diameter in an undeployed position, and a seconddiameter in a deployed position, and the second diameter is greater thanthe first diameter. In some embodiments, the extendible rail furthercomprises an outer rail; and an inner rail slidingly engaged within theouter rail in a telescoping manner, such that in the undeployedposition, the inner rail is disposed substantially entirely within theouter rail, and, in the deployed position, at least a portion of theinner rail is exposed. In some embodiments, the deployable guard devicefurther comprises: a support track, configured to be secured to theportable imaging device; and one or more swing arms, connected at afirst end thereof to the support track and connected to the outer railat a second end thereof. In some embodiments, the one or more swing armsare disposed substantially within the support track when the deployableguard device is in the undeployed position. In some embodiments, thesecond end of the one or more swing arms arm is extended in a radiallyoutward direction from the support track in the deployed position. Insome embodiments, the defined magnetic field strength is within a rangefrom about 1 Gauss to about 30 Gauss. In some embodiments, the definedmagnetic field strength is within a range from about 5 Gauss to about 20Gauss.

In some embodiments, when in an undeployed position, the deployableguard device defines a first inner region having a first area; andwherein, when in a deployed position, the deployable guard devicedefines a second inner region having a second area larger than the firstarea. In some embodiments, the deployable guard device is configured tobe deployed manually from the undeployed position to the deployedposition. In some embodiments, the deployable guard device is configuredto be moved manually from the deployed position to the undeployedposition. In some embodiments, the deployable guard device is configuredto be deployed mechanically from the undeployed position to the deployedposition. In some embodiments, the deployable guard device is configuredto be moved mechanically from the deployed position to the undeployedposition. In some embodiments, the deployable guard device is configuredto be deployed pneumatically from the undeployed position to thedeployed position. In some embodiments, the deployable guard device isconfigured to be moved pneumatically from the deployed position to theundeployed position. In some embodiments, the deployable guard device isconfigured to be deployed hydraulically from the undeployed position tothe deployed position. In some embodiments, the deployable guard deviceis configured to be moved hydraulically from the deployed position tothe undeployed position.

In some embodiments, the deployable guard device is substantiallyradially symmetrical. In some embodiments, the deployable guard devicefurther comprises: multiple arcuate sections, including a first arcuatesection, wherein: when the deployable guard device is in a deployedposition, a first point on the first arcuate section is at a firstdistance from an isocenter of the deployable guard device, and a secondpoint on the first arcuate second is at a second distance from theisocenter, and wherein the first and second distances are different fromeach other. In some embodiments, the multiple arcuate sections eachcomprise a first rail and a second rail slidingly engaged with the firstrail. In some embodiments, the first rail comprises a slotted trackconfigured to receive the second rail.

Some embodiments include a system comprising a portable medical imagingdevice; and a deployable guard device, coupled to the portable medicalimaging device, the deployable guard device configured to, whendeployed, inhibit encroachment within a physical boundary with respectto the portable medical imaging device.

In some embodiments, the portable medical imaging device comprises amagnetic resonance imaging (MRI) device, and the physical boundarycorresponds to a volume that encompasses a region having a definedmagnetic strength. In some embodiments, the deployable guard devicecomprises an extendible rail. In some embodiments, the extendible railhas a first diameter in an undeployed position, and a second diameter ina deployed position, and the second diameter is greater than the firstdiameter. In some embodiments, the extendible rail further comprises: anouter rail; and an inner rail slidingly engaged within the outer rail ina telescoping manner, such that in the undeployed position, the innerrail is substantially entirely within the outer rail, and in thedeployed position, at least a portion of the inner rail is exposed. Insome embodiments, the deployable guard device further comprises: asupport track, configured to be secured to the portable medical imagingdevice; and one or more swing arms, connected at a first end thereof tothe support track and connected to the outer rail at a second endthereof.

In some embodiments, the one or more swing arms are disposedsubstantially within the support track within the deployable guarddevice is in the undeployed position. In some embodiment, the second endof the one or more swing arms is extended in a radially outwarddirection from the support track in the deployed position. In someembodiments, the defined magnetic field strength is within a range fromabout 1 Gauss to about 30 Gauss. In some embodiments, wherein thedefined magnetic field strength is within a range from about 5 Gauss toabout 20 Gauss.

In some embodiments, when in an undeployed position, the deployableguard device defines a first inner region having a first area; andwherein, when in a deployed position, the deployable guard devicedefines a second inner region having a second area larger than the firstarea. In some embodiments, the deployable guard device is configured tobe deployed manually from the undeployed position to the deployedposition. In some embodiments, the deployable guard device is configuredto be moved manually from the deployed position to the undeployedposition. In some embodiments, the deployable guard device is configuredto be deployed mechanically from the undeployed position to the deployedposition. In some embodiments, the deployable guard device is configuredto be moved mechanically from the deployed position to the undeployedposition. In some embodiments, the deployable guard device is configuredto be deployed pneumatically from the undeployed position to thedeployed position. In some embodiments, the deployable guard device isconfigured to be moved pneumatically from the deployed position to theundeployed position. In some embodiments, the deployable guard device isconfigured to be deployed hydraulically from the undeployed position tothe deployed position. In some embodiments, the deployable guard deviceis configured to be moved hydraulically from the deployed position tothe undeployed position.

In some embodiments, the deployable guard device is substantiallyradially symmetrical. In some embodiments, the deployable guard devicefurther comprises: multiple arcuate sections, including a first arcuatesection, wherein: when the deployable guard device is in a deployedposition, a first point on the first arcuate section is at a firstdistance from an isocenter of the deployable guard device; and a secondpoint on the first arcuate section is at a second distance from theisocenter, and wherein the first and second distances are different fromeach other. In some embodiments, the multiple arcuate sections eachcomprise a first rail and a second rail slidingly engaged with the firstrail. In some embodiments, the first rail comprises a slotted trackconfigured to receive the second rail.

In some embodiments, the deployable guard device is coupled to theportable medical imaging device below an imaging region of the portablemedical imaging device and above a base of the portable medical imagingdevice. In some embodiments, the base supports a magnetics system of theportable medical imaging device and houses a power system, the basecomprising at least one conveyance mechanism allowing the portablemedical imaging device to be transported to different locations; and thepower system comprises one or more power components configured toprovide power to the magnetics system to operate the portable medicalimaging device to perform image acquisition. In some embodiments, thedeployable guard device is couple to the portable medical imaging deviceabove an imaging region of the portable medical imaging device. In someembodiments, the system further comprises a second deployable guarddevice coupled to the portable medical imaging device above the imagingregion.

Some embodiments include an apparatus comprising a deployable guarddevice, configured to be coupled to a portable magnetic resonanceimaging system, the deployable guard device further configured to, whendeployed, demarcate a boundary within which a magnetic field strength ofa magnetic field generated by the portable magnetic resonance imagingsystem equals or exceeds a given threshold.

Some embodiments include a deployable guard device, comprising: an innerportion configured to be coupled to a portable magnetic resonanceimaging device; a plurality of swing arms movably coupled to the innerportion; and an outer portion movable coupled to the plurality of swingarms.

In some embodiments, the inner portion is substantially circular. Insome embodiments, the outer portion is substantially circular. In someembodiments, the outer portion comprises multiple arcuate sectionsincluding a first arcuate section, wherein: when the deployable guarddevice is in a deployed position, a first point on the first arcuatesection is at a first distance from an isocenter of the deployable guarddevice, and a second point on the first arcuate section is at a seconddistance from the isocenter, and wherein the first and second distancesare different from each other. In some embodiments, when in anundeployed position, the deployable guard device defines a first innerregion having a first area; and wherein, when in a deployed position,the deployable guard device defines a second inner region having asecond area larger than the first area.

In some embodiments, the deployable guard device is configured to bedeployed manually from the undeployed position to the deployed position.In some embodiments, the deployable guard device is configured to bemoved manually from the deployed position to the undeployed position. Insome embodiments, the deployable guard device is configured to bedeployed mechanically from the undeployed position to the deployedposition. In some embodiments, the deployable guard device is configuredto be moved mechanically from the deployed position to the undeployedposition. In some embodiments, the deployable guard device is configuredto be deployed pneumatically from the undeployed position to thedeployed position. In some embodiments, the deployable guard device isconfigured to be moved pneumatically from the deployed position to theundeployed position. In some embodiments, the deployable guard device isconfigured to be deployed hydraulically from the undeployed position tothe deployed position. In some embodiments, the deployable guard deviceis configured to be moved hydraulically from the deployed position tothe undeployed position.

In some embodiments, the plurality of swing arms comprises at least fourswing arms. In some embodiments, the outer portion further comprises: anouter rail; and an inner rail slidingly engaged with the outer rail in atelescoping manner, such that in an undeployed position, the inner railis disposed substantially entirely within the outer rail, and, in adeployed position, at least a portion of the inner rail is exposed. Insome embodiments, the inner portion is configured to be coupled to abase of the portable magnetic resonance imaging device, wherein: thebase supports a magnetics system of the portable magnetic resonanceimaging device and houses a power system, the base comprising at leastone conveyance mechanism allowing the portable medical imaging device tobe transported to different locations; and the power system comprisesone or more power components configured to provide power to themagnetics system to operate the portable medical imaging device toperform image acquisition. In some embodiments, the inner portion isconfigured to be coupled to the portable magnetic resonance imagingdevice through a plurality of mounting tabs. In some embodiments, theplurality of mounting tabs comprises four or more mounting tabs.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects and embodiments of the application will be describedwith reference to the following figures. It should be appreciated thatthe figures are not necessarily drawn to scale. Items appearing inmultiple figures are indicated by the same reference number in all thefigures in which they appear.

FIG. 1 is an exemplary portable medical imaging device for use inaccordance with some embodiments of the technology described herein.

FIGS. 2A, 2B and 2C are top, front and side views of a portable medicalimaging device, for example of the portable medical imaging device shownin FIG. 1 , illustrating example magnetic fringe fields associated withthe device.

FIG. 3A illustrates the portable medical imaging device of FIG. 1 with adeployable guard device having a “hoop” design, shown in a deployedposition, and coupled to the portable medical imaging device below itsB₀ magnet, in accordance with some embodiments of the technologydescribed herein.

FIG. 3B illustrates the portable medical imaging device of FIG. 1 with adeployable guard device having a “hoop” design, shown in a deployedposition, and coupled to the portable medical imaging device above itsB₀ magnet, in accordance with some embodiments of the technologydescribed herein.

FIG. 3C illustrates the portable medical imaging device of FIG. 1 with adeployable guard device having a “hoop” design, shown in an undeployedposition, and coupled to the portable medical imaging device above itsB₀ magnet, in accordance with some embodiments of the technologydescribed herein.

FIG. 3D illustrates the portable medical imaging device of FIG. 1 with adeployable guard device having a “clover” design, shown in a deployedposition, and coupled to the portable medical imaging device below itsB₀ magnet, in accordance with some embodiments of the technologydescribed herein.

FIG. 3E illustrates the portable medical imaging device of FIG. 1 with adeployable guard device having a “clover” design, shown in a deployedposition, and coupled to the portable medical imaging device above itsB₀ magnet, in accordance with some embodiments of the technologydescribed herein.

FIG. 4 illustrates the portable medical imaging device configured withthe hoop-shaped deployable guard device of FIG. 3A, particularlyillustrating a physical boundary in relationship to the guard, inaccordance with some embodiments of the technology described herein.

FIG. 5 illustrates the portable medical imaging device of FIG. 1 ,configured with two hoop-shaped deployable guard devices, in accordancewith some embodiments of the technology described herein.

FIG. 6 illustrates a first exemplary environment for a portable medicalimaging device configured with one or more deployable guard devices, inaccordance with some embodiments of the technology described herein.

FIG. 7 illustrates a second exemplary environment for a portable medicalimaging device configured with one or more deployable guard devices inaccordance with some embodiments of the technology described herein.

FIG. 8 illustrates a third exemplary environment for a portable medicalimaging device configured with one or more deployable guard devices inaccordance with some embodiments of the technology described herein.

FIG. 9 illustrates a base portion of a portable medical imaging deviceconfigured with a deployable guard device in an undeployed position, inaccordance with some embodiments of the technology described herein.

FIG. 10 illustrates the base portion of the medical imaging device ofFIG. 9 configured with the deployable guard device having a “hoop”design and in a deployed position, in accordance with some embodimentsof the technology described herein.

FIG. 11 illustrates a swing arm of a deployable guard device, inaccordance with some embodiments of the technology described herein.

FIG. 12 illustrates a support track of a deployable guard device, inaccordance with some embodiments of the technology described herein.

FIGS. 13A-E illustrate views of a deployable guard device having a“clover” design, including views of the guard in deployed and undeployedconfigurations, in accordance with some embodiments of the technologydescribed herein.

FIGS. 14A-D illustrate views of a support track of a deployable guarddevice having a “clover” design, in accordance with some embodiments ofthe technology described herein.

FIGS. 15A-D illustrate views of a mounting tab of a deployable guarddevice having a “clover” design, in accordance with some embodiments ofthe technology described herein.

FIGS. 16A-C illustrate views of a swing arm of a deployable guard devicehaving a “clover” design, in accordance with some embodiments of thetechnology described herein.

FIGS. 17A-B illustrate views of a rail portion of a deployable guarddevice having a “clover” design, in accordance with some embodiments ofthe technology described herein.

FIG. 18A-C illustrate views of another rail portion of the deployableguard device having a “clover” design, in accordance with someembodiments of the technology described herein.

FIGS. 19A-F illustrate views of a deployable guard device having a“hoop” design, in accordance with some embodiments of the technologydescribed herein.

FIGS. 20A-D illustrate views a support track of the deployable guarddevice having a “hoop” design, in accordance with some embodiments ofthe technology described herein.

FIGS. 21A-E illustrate views of a mounting tab of a deployable guarddevice having a “hoop” design, in accordance with some embodiments ofthe technology described herein.

FIGS. 22A-C illustrate views of a swing arm of a deployable guard devicehaving a “hoop” design, in accordance with some embodiments of thetechnology described herein.

FIGS. 23A-H illustrate views of a hinge having ball detents of a supporttrack of a deployable guard device having a “hoop” design, in accordancewith some embodiments of the technology described herein.

FIGS. 24A-C illustrate views of inner and outer rails of a deployableguard device having a “hoop” design, in accordance with some embodimentsof the technology described herein.

DETAILED DESCRIPTION

The MRI scanner market is overwhelmingly dominated by high-fieldsystems, and is exclusively so for medical or clinical MRI applications.As discussed above, the general trend in medical imaging has been toproduce MRI scanners with increasingly greater field strengths, with thevast majority of clinical MRI scanners operating at 1.5 T or 3 T, withhigher field strengths of 7 T and 9 T used in research settings. As usedherein, “high-field” refers generally to MRI systems presently in use ina clinical setting and, more particularly, to MRI systems operating witha main magnetic field (i.e., a B₀ field) at or above 1.5 T, thoughclinical systems operating between 0.5 T and 1.5 T are often alsocharacterized as “high-field.” Field strengths between approximately 0.2T and 0.5 T have been characterized as “mid-field” and, as fieldstrengths in the high-field regime have continued to increase, fieldstrengths in the range between 0.5 T and 1 T have also beencharacterized as mid-field. By contrast, “low-field” refers generally toMRI systems operating with a B₀ field of less than or equal toapproximately 0.2 T, though systems having a B₀ field of between 0.2 Tand approximately 0.3 T have sometimes been characterized as low-fieldas a consequence of increased field strengths at the high end of thehigh-field regime. Within the low-field regime, low-field MRI systemsoperating with a B₀ field of less than 0.1 T are referred to herein as“very low-field” and low-field MRI systems operating with a B₀ field ofless than 10 milliTesla (mT) are referred to herein as “ultra-lowfield”.

The appeal of high-field MRI systems include improved resolution and/orreduced scan times compared to lower field systems, motivating the pushfor higher and higher field strengths for clinical and medical MRIapplications. However, as also discussed above, increasing the fieldstrength of MRI systems yields increasingly more expensive and complexMRI scanners, thus limiting availability and preventing their use as ageneral purpose and/or generally available imaging solution.

Low-field MRI has been explored in limited contexts for non-imagingresearch purposes and narrow and specific contrast-enhanced imagingapplications, but is conventionally regarded as being unsuitable forproducing clinically useful images. For example, the resolution,contrast, and/or image acquisition time is generally not regarded asbeing suitable for clinical purposes such as, but not limited to, tissuedifferentiation, blood flow or perfusion imaging, diffusion-weighted(DW) or diffusion tensor (DT) imaging, functional MRI (fMRI), etc.

More recently, certain advancements (such as those developed by theassignee of the instant application) have paved the way for improvedquality, portable and/or lower-cost low-field MRI systems that can, inturn, drive wide-scale deployability of MRI technology in a variety ofenvironments beyond the large MRI installments at hospitals and researchfacilities. As such, low-field MRI presents an attractive imagingsolution, providing a relatively low cost, high availability alternativeto high-field MRI. In particular, low-field MRI systems can beimplemented as self-contained systems that are deployable in a widevariety of clinical settings where high-field MRI systems cannot, forexample, by virtue of being transportable, cartable or otherwisegenerally mobile so as to be deployable where needed. As a result ofthis portability, such low-field MRI systems may be expected to operatein generally unshielded or partially shielded environments (e.g.,outside of specially shielded rooms or encompassing cages) while alsohandling the particular noise environment in which they are deployed.

The inventors have recognized that with the emergence of a new paradigmfor MRI, certain additional challenges may arise with respect to aportable, point-of-care (POC) MRI system that can be installed in avariety of settings such as an emergency room, office or clinic. Forexample, when in storage or when transported from location to location,a portable, low-field POC MRI system (including any of the systemsdescribed herein) may temporarily reside in (or pass through) an area orareas that are not access controlled. On the one hand, a low-fieldsystem MRI system operates at a static magnetic field much lower thanthat of conventional high-field MRI systems, and as such certain riskstypically associated with high-field systems (e.g., potential projectileeffects) are likely absent. On the other hand, there still may be otherconcerns associated with having even low-level static magnetic fieldspresent in areas that are not access controlled. Examples of suchconcerns may include, but are not necessarily limited to: individualshaving active implants (e.g., pacemakers, defibrillators, insulin pumps,deep brain stimulators, vagus nerve stimulators, cochlear implants,etc.) in the vicinity of the MRI system; individuals with metalcontaining tattoos or permanent make-up on the head or neck regions inthe vicinity of the MRI system; and individuals with suspected metalpresent in the eye (e.g., metal workers, injury victim, etc.) in thevicinity of the MRI system.

High fringe fields may be dangerous to bystanders for the reasonsdiscussed herein, however low-strength fringe fields (e.g., fringefields having a strength of less than 30 Gauss, less than 25 Gauss, lessthan 20 Gauss, less than 15 Gauss, less than 10 Gauss, less than 5Gauss, less than 2 Gauss, less than 1 Gauss, any strength in the rangeof 2-10 Gauss or 2-20 Gauss, etc.) may be tolerated because suchlow-strength fringe fields may not present a safety concern or otherwiseinterfere with operation of nearby electronics including implants (e.g.,pacemakers) or other electronic devices (e.g., medical instruments,smartphones, etc.).

In some environments, safety regulations may require indications of theboundary or perimeter within which the magnetic field of the MRI systemexceeds a given threshold field strength. These boundaries are sometimescalled “Gauss lines.” A Gauss line for a device may indicate a region,outside of which, the strength of a magnetic field generated by thedevice is less than a threshold strength. For example, the 5 Gauss linefor an MRI device may indicate a region outside of which the magneticfield generated by the MRI device has a strength of less than 5 Gauss.Magnetic fields having strength higher than 30 Gauss may presentprojectile hazards. Some safety regulations may require the 5, 10 and200 Gauss lines to be indicated to demarcate the physical perimeterswithin which the respective thresholds are exceeded.

It should be appreciated that such challenges are generally not ofconcern with respect to the more conventional, high field MRI systemsthat are typically immobile and installed in specialized rooms withextensive shielding and defined access control protocols. For example,compliance with the above-mentioned safety regulations may be achievedby indicating the 5, 10 and 200 Gauss lines on the floor of the room inwhich the MRI system is installed, to remind personnel where therespective protocols need to be enforced. This solution is generallyinapplicable in the context of portable MRI systems because theperimeters requiring demarcation would need to move along with the MRIdevice. In view of this and as described herein, embodiments of thedisclosure provide for a deployable guard device, configured to becoupled to a portable medical imaging device. When deployed, thedeployable guard device is configured to inhibit encroachment within aphysical boundary with respect to the portable medical imaging device.

The inventors have recognized that the inclusion of a deployable guardcoupled to the portable medical imaging device is particularly importantin embodiments in which the portable medical imaging device includes oneor more permanent magnets. Unlike other magnetic assemblies, a magneticscomponent comprising a permanent magnet produces fringe fields bothduring operation of the medical imaging device and during transport andstorage of the medical imaging device when the portable medical imagingdevice is otherwise not being operated. As described herein, transportand storage of the portable medical imaging device may involve thedevice entering uncontrolled areas where bystanders may be present, suchas a hallway as illustrated in FIG. 6 . Thus, when a portable medicalimaging device includes one or more permanent magnets (e.g., to generatethe B₀ field), it is important to provide a physical boundarydemarcating the region in which it is unsafe for bystanders orelectronic devices to enter due to fringe fields produced duringoperation, transport, and storage of the portable medical imagingdevice.

In some embodiments, the deployable guard device may be configured toprovide a physical boundary corresponding to a particular Gauss line.For example, in some embodiments, the deployable guard device, when in adeployed position, may provide a physical barrier to encroachment suchthat the region within the physical barrier includes a particular Gaussline (e.g., the 5 Gauss line, the 10 Gauss line, etc.). To this end, thedeployable guard device may be configured such that, when deployed, theouter perimeter of the deployable guard device extends beyond theparticular Gauss line relative to the portable MR system to which thedeployable guard device is coupled.

For ease of explanation, embodiments of a deployable guard devicedisclosed herein are described in the context of a portable POC MRIsystem; however, it should be appreciated that such a guard device mayalso be used in conjunction with other devices including, but notlimited to, X-ray images, CT imaging devices, etc.

Referring initially to FIG. 1 , there is shown an exemplary portablemedical imaging device 100 (also referred to herein as a portable MRIsystem) for use in accordance with embodiments of the technologydescribed herein. In the embodiment depicted in FIG. 1 , the portablemedical imaging device 100 may be a POC MRI system including a B₀ magnet104 having at least one first permanent magnet 106 a and at least onesecond permanent magnet 106 b magnetically coupled to one another by aferromagnetic yoke 108 configured to capture and channel magnetic fluxto increase the magnetic flux density within the imaging region (fieldof view) of the MRI system 100. Alternatively, in some embodiments, B₀magnet 104 may be formed using electromagnets, laminate magnets, orhybrid magnets. Additional information regarding the formation of B₀magnet 104 may be found in U.S. Patent Publication No. US 2018/0143274,filed Nov. 22, 2017 and titled “Low-Field Magnetic Resonance ImagingMethods and Apparatus”, hereby incorporated by reference.

In some embodiments, the B₀ magnet 104 may be coupled to or otherwiseattached or mounted to a base 110 by a positioning mechanism 112 (suchas for example a goniometric stage) so that the B₀ magnet can be tilted(e.g., rotated about its center of mass) to provide an incline toaccommodate a patient's anatomy as needed. In addition to providing aload bearing structure(s) for supporting the B₀ magnet 104, the base 110may also include an interior space or compartment(s) configured to housethe electronics (not shown) used to operate the portable MRI system 100.For example, the base 110 may house power components to operate gradientcoils (e.g., X, Y and Z) and RF transmit/receive coils, as well as RFcoil amplifiers (power amplifiers to operate the transmit/receive coilsof the system), power supplies, console, power distribution unit andother electronics needed to operate the MRI system.

In some embodiments, the electronics needed to operate portable MRIsystem 100 may consume less than 1 kW of power and, in some embodiments,less than 750 W of power (e.g., MRI systems utilizing a permanent B₀magnet solution). However, systems that consume greater power may alsobe utilized as well, as the aspects of the technology described hereinare not limited in this respect. As such, the exemplary portable MRIsystem 100 may be powered via a single power connection 114 configuredto connect to a source of mains electricity, such as an outlet providingsingle-phase power (e.g., a standard or large appliance outlet).Accordingly, the portable MRI system 100 can be plugged into a singleavailable power outlet and operated therefrom. Aspects of power systemsthat may be used as part of portable MRI system 100 are described inU.S. Patent Publication No. US 2018/0143274, filed Nov. 22, 2017 andtitled “Low-Field Magnetic Resonance Imaging Methods and Apparatus”,which is incorporated by reference in its entirety.

As further illustrated in FIG. 1 , the portable MRI system 100 may alsoinclude a conveyance mechanism 116 that allows the portable MRI system100 to be transported to different locations. The conveyance mechanism116 may include one or more components configured to facilitate movementof the portable MRI system 100, for example, to a location at which MRIis needed. According to some embodiments, conveyance mechanism 116 mayinclude a motor 118 coupled to drive wheels 120. In this manner, theconveyance mechanism 116 provides motorized assistance in transportingthe MRI system 100 to desired locations. Additionally, the conveyancemechanism 116 may also include a plurality of casters 122 to assist withsupport and stability as well as facilitating transport.

In some embodiments, the conveyance mechanism 116 may optionally includemotorized assistance controlled via a joystick (not shown) to guide theportable MRI system 100 during transportation to desired locations.According to some embodiments, the conveyance mechanism 116 may alsoinclude a power assist mechanism configured to detect when force isapplied to the MRI system and, in response, to engage the conveyancemechanism 116 to provide motorized assistance in the direction of thedetected force. For example, handles 124 may be configured to detectwhen force is applied thereto the rail (e.g., by personnel pushing onthe handles 124) and engage the conveyance mechanism 116 to providemotorized assistance to drive the wheels 120 in the direction of theapplied force. As a result, a user can guide the portable MRI system 100with the assistance of the conveyance mechanism 116 that responds to thedirection of force applied by the user.

As indicated above, although the portable MRI system 100 operates at aB₀ field strength well below that of a traditional high-field system,there still may be concerns with access control, given certain fringefield strengths around an isocenter 200 of the B₀ magnet 104. By way ofillustration, FIGS. 2A, 2B and 2C are top, front and side views,respectively of a portable medical imaging device, for example, thedevice shown in FIG. 1 . For example, an innermost region (defined bydimensions H1 and H2) may represent a 30 Gauss region and an outermostregion (defined by dimensions L1 and L2) may represent a 5 Gauss region,wherein the fringe field strength decreases with increasing distancefrom the isocenter 200. Thus, one consideration in this regard may be,for example, the International Electrotechnical Commission (IEC)60601-2-33 standard, which defines controlled access as an area to whichaccess is controlled for safety reasons. The standard further specifiesthat a controlled access area around the MR equipment shall be definedsuch that outside this area: 1) the magnetic fringe field strength shallnot exceed 0.5 mT and 2) the electromagnetic interference level complieswith IEC 60601-1-2.

Accordingly, FIG. 3A illustrates the portable medical imaging device 100of FIG. 1 with a deployable guard device 300 having a “hoop” design,shown in a deployed position, and coupled to the portable medicalimaging device below its B₀ magnet, in accordance with some embodimentsof the technology described herein. The deployable guard device 300 inFIG. 3A is illustrated having a “hoop” design. In the illustratedembodiment, the deployable guard device 300 includes a support track904, one or more swing arms 910, one or more hollow collars 912, aninner rail 908, an outer rail 902, and one or more Velcro straps 904, asdescribed herein including with reference to FIGS. 9-10 . As shown inFIG. 3A, the device 300 has a substantially radially symmetric design.For example, the diameter of an inner region defined by the deployableguard device 300 having the “hoop” design may be substantially equal atall points along the deployable guard device 300 having the “hoop”design when the device 300 is in the deployed position or the undeployedposition, respectively. Aspects of the deployable guard device 300 aredescribed herein including with reference to FIGS. 9-12 , FIGS. 19-24 .

In some embodiments, the support track 904 of the deployable guarddevice 300 having the “hoop” design may be formed from a material suchas stainless steel. In some embodiments, outer rail 902 and inner rail908 may be formed from PVC, plastic, or other suitable material(s). Forexample, the outer rail 904 and inner rail 902 may be formed frompolyethylene. In some embodiments, the one or more swing arms 910 andone or more hollow collars 912 may be formed from aluminum or othersuitable material(s). In some embodiments, the one or more swing arms910, one or more hollow collars 912, support track 904, outer rail 902and inner rail 908 may all be formed from a plastic material, such aspolyethylene, for example.

In the illustrated embodiment, the deployable guard device 300 iscoupled to the portable medical imaging device 100. The deployable guarddevice 300 may be coupled to the portable medical imaging device in anysuitable way including by way of example: (1) below the B₀ magnet 104and above the base 110 of the portable medical imaging device 100 (e.g.,as shown in FIG. 3A); (2) below the first permanent magnet 106 a andabove the second permanent magnet 106 b; (3) or above the firstpermanent magnet 106 a. The base 110 may provide a load bearingstructure(s) for supporting the B₀ magnet 104 and may also include aninterior space or compartment(s) configured to house electronics used tooperate the portable medical imaging device 100.

The deployable guard device 300 in FIG. 3A is illustrated in a deployedposition. When the deployable guard device 300 is in the undeployedposition, the device 300 defines a first inner region 210A illustratedin FIG. 9 , having a first area. When the deployable guard device 300 isin the deployed position, the device 300 defines a second inner region210B illustrated in FIG. 10 , having a second area larger than the firstarea. Therefore, the area of the inner region defined by the deployableguard device 300 is increased when the deployable guard device 300 istransitioned from the undeployed position to the deployed position.

FIG. 3B illustrates the portable medical imaging device 100 of FIG. 1with a second deployable guard device 500 having a “hoop” design shownin a deployed position, and coupled to the portable medical imagingdevice 100 above its B₀ magnet, in accordance with some embodiments ofthe technology described herein. The second deployable guard device 500illustrated in FIG. 3B is configured having the “hoop” design describedherein. Aspects of the second deployable guard device 500 are describedherein including with reference to FIGS. 9-12 , FIGS. 19-24 .

In the illustrated embodiment, the second deployable guard device 500 iscoupled to the portable medical imaging device 100. The seconddeployable guard device 500 may be coupled to the portable medicalimaging device, for example, below the B₀ magnet 104 and above the base110 of the portable medical imaging device 100, below the firstpermanent magnet 106 a and above the second permanent magnet 106 b, orabove the first permanent magnet 106 a (e.g., as shown in FIG. 3B), asthe embodiments of the technology disclosed herein are not limited inthis respect.

The second deployable guard device 500 in FIG. 3B is illustrated in adeployed position, although the second deployable guard device 500 maybe configured in an undeployed position in addition to the deployedposition as is illustrated in FIG. 3C. When the second deployable guarddevice 500 is in the undeployed position, the device 500 defines a firstinner region 210A illustrated in FIG. 9 , having a first area. When thesecond deployable guard device 500 is in the deployed position, thedevice 500 defines a second inner region 210B illustrated in FIG. 10 ,having a second area larger than the first area. Therefore, the area ofthe inner region defined by the second deployable guard device 500 isincreased when the second deployable guard device 500 is transitionedfrom the undeployed position to the deployed position.

FIG. 3C illustrates the portable medical imaging device 100 of FIG. 1with a deployable guard device 500 having a “hoop design”, shown in anundeployed position, and coupled to the portable medical imaging device100 above its B₀ magnet, in accordance with some embodiments of thetechnology described herein. The second deployable guard device 500illustrated in FIG. 3C is configured having the “hoop” design describedherein. Aspects of the second deployable guard device 500 are describedherein including with reference to FIGS. 9-12 , FIGS. 19-24 .

In the illustrated embodiment, the second deployable guard device 500 iscoupled to the portable medical imaging device 100. The seconddeployable guard device 500 may be coupled to the portable medicalimaging device, for example, below the B₀ magnet 104 and above the base110 of the portable medical imaging device 100, below the firstpermanent magnet 106 a and above the second permanent magnet 106 b, orabove the first permanent magnet 106 a (e.g., as shown in FIG. 3C), asthe embodiments of the technology disclosed herein are not limited inthis respect.

The second deployable guard device 500 in FIG. 3C is illustrated in anundeployed position, although the second deployable guard device 500 maybe configured in a deployed position in addition to the deployedposition as is illustrated in FIG. 3B. When the second deployable guarddevice 500 is in the undeployed position, the device 500 defines a firstinner region 210A illustrated in FIG. 9 , having a first area. When thesecond deployable guard device 500 is in the deployed position, thedevice 500 defines a second inner region 210B illustrated in FIG. 10 ,having a second area larger than the first area. Therefore, the area ofthe inner region defined by the second deployable guard device 500 isincreased when the second deployable guard device 500 is transitionedfrom the undeployed position to the deployed position.

FIG. 3D illustrates the portable medical imaging device 100 of FIG. 1with a deployable guard device 301 having a “clover” design, shown in adeployed position, and coupled to the portable medical imaging devicebelow its B₀ magnet, in accordance with some embodiments of thetechnology described herein. The deployable guard device 301 in FIG. 3Dis illustrated having a “clover” design. The “clover” design maycomprise a support track 904, one or more swing arms 910, one or morefirst rail portions 1008, and one or more second rail portions 1002 eachhaving a slotted track 1010, as described herein. The “clover” designmay comprise one or more arcuate sections 1012A-D, each of the arcuatesections 1012A-D may be substantially symmetrical with respect to eachother. When the deployable guard device 301 having the “clover” designis in the undeployed position, the diameter of a first inner region 210Cillustrated in FIG. 13D, defined by the deployable guard device 301having the “clover” design may be substantially equal at all pointsalong the deployable guard device 301. When the deployable guard device301 having the “clover” design is in the undeployed position, thediameter of a second inner region 210D illustrated in FIG. 13A, definedby the deployable guard device 301 having the “clover” design may varyat points along the first and second rail portions 1008, 1002 of thedeployable guard device. Aspects of the deployable guard device 301 aredescribed herein including with reference to FIGS. 13-18 .

The support track 904 of the deployable guard device 301 having the“clover” design may be formed from a material such as stainless steel.First and second rail portions 1008, 1002 and the one or more swing arms910 may be formed from aluminum or other suitable material(s). In someembodiments, the one or more swing arms 910, support track 904, firstrail portion 1008 and second rail portion 1002 may all be formed from aplastic material, such as polyethylene, for example.

In the illustrated embodiment, the deployable guard device 301 iscoupled to the portable medical imaging device 100. The deployable guarddevice 301 may be coupled to the portable medical imaging device, forexample, below the B₀ magnet 104 and above the base 110 of the portablemedical imaging device 100 (e.g., as shown in FIG. 3D), below the firstpermanent magnet 106 a and above the second permanent magnet 106 b, orabove the first permanent magnet 106 a, as the embodiments of thetechnology disclosed herein are not limited in this respect. The base110 may provide a load bearing structure(s) for supporting the B₀ magnet104 and may also include an interior space or compartment(s) configuredto house electronics used to operate the portable medical imaging device100.

The deployable guard device 301 in FIG. 3D is illustrated in a deployedposition, although the deployable guard device 301 may be configured inan undeployed position in addition to the deployed position. When thedeployable guard device 301 is in the undeployed position, the device301 defines a first inner region 210C illustrated in FIG. 13D, having afirst area. When the deployable guard device 301 is in the deployedposition, the device 301 defines a second inner region 210D illustratedin FIG. 13A, having a second area larger than the first area. Therefore,the area of the inner region defined by the deployable guard device 301is increased when the deployable guard device 301 is transitioned fromthe undeployed position to the deployed position.

FIG. 3E illustrates the portable medical imaging device 100 of FIG. 1with a deployable guard device 501 having a “clover” design, shown in adeployed position, and coupled to the portable medical imaging deviceabove its B₀ magnet, in accordance with some embodiments of thetechnology described herein. The second deployable guard device 501 inFIG. 3E is illustrated having a “clover” design. Aspects of the seconddeployable guard device 501 are described herein including withreference to FIGS. 13-18 .

In the illustrated embodiment, the second deployable guard device 501 iscoupled to the portable medical imaging device 100. The seconddeployable guard device 501 may be coupled to the portable medicalimaging device, for example, below the B₀ magnet 104 and above the base110 of the portable medical imaging device 100, below the firstpermanent magnet 106 a and above the second permanent magnet 106 b, orabove the first permanent magnet 106 a (e.g., as shown in FIG. 3E), asthe embodiments of the technology disclosed herein are not limited inthis respect.

The second deployable guard device 501 in FIG. 3E is illustrated in adeployed position, although the second deployable guard device 501 maybe configured in an undeployed position in addition to the deployedposition. When the second deployable guard device 501 is in theundeployed position, the device 501 defines a first inner region 210Cillustrated in FIG. 13D, having a first area. When the second deployableguard device 501 is in the deployed position, the device 501 defines asecond inner region 210D illustrated in FIG. 13A, having a second arealarger than the first area. Therefore, the area of the inner regiondefined by the second deployable guard device 501 is increased when thesecond deployable guard device 501 is transitioned from the undeployedposition to the deployed position.

As described in further detail herein, when the deployable guard deviceaccording to embodiments of the technology described herein is deployed,it serves as a physical barrier to inhibit encroachment within a definedregion having a certain magnetic field strength. In one specificexample, a defined region 400 is illustrated in FIG. 4 . As can be seen,when the deployable guard device 300 is in the deployed position, thedevice 300 extends beyond the region 400 (e.g., 1 Gauss, G gauss, 10Gauss, 20 Gauss, etc.) such that the guard device 300 is capable ofinhibiting physical encroachment within this region. Therefore, theguard device according to the embodiments described herein is capable ofdemarcating any strength Gauss line as desired.

In an alternative embodiment, and as a further measure to inhibitencroachment along an entire vertical height of the region 400, FIG. 5illustrates an embodiment of the disclosure in which the portable MRIsystem 100 is configured with a first hoop-shaped deployable guarddevice 300 and a second hoop-shaped deployable guard device 500, inaccordance with some embodiments of the technology described herein. Inthis manner, both the first deployable guard device 300 and the seconddeployable guard device 500 extend beyond the boundary of the region400, which inhibits a bystander 502 from encroaching within the region400. It should be appreciated that such a configuration having both afirst deployable guard device and a second deployable guard device mayutilize a deployable guard device according to any embodiment describedherein. For example, although FIG. 5 illustrates the first and seconddeployable guard devices having a “hoop” design, it should be understoodthat a deployable guard device having a “clover” design as describedherein may be used interchangeably in place of first deployable guarddevice 300, second deployable guard device 500, or both first deployableguard device 300 and second deployable guard device 500.

One or more guard devices may be utilized in a number of ways withrespect to a portable MRI system. For example, FIG. 6 illustrates afirst exemplary environment for a portable medical imaging device 100configured with one or more deployable guard devices, in accordance withsome embodiments of the technology described herein. As shown in FIG. 6, when the system 100 is in transit (e.g., through a hallway 600 orother common corridor), in storage or in any environment with anuncertain degree of access control, one or more guard devices 300, 500may be deployed. In contrast, where the system 100 has been brought toand set up within a patient room 700, the room 700 may become thecontrolled access area through applicable signage 702 that is placed onthe room door 704, for example as set forth in IEC 60601-2-33.

As illustrated in FIG. 7 , there is shown a second exemplary environmentfor a portable medical imaging device 100 configured with one or moredeployable guard devices in accordance with some embodiments of thetechnology described herein. FIG. 8 illustrates a third exemplaryoperating environment for a portable MRI system 100 configured with oneor more deployable guard devices in accordance with some embodiments ofthe technology described herein that may represent an intermediatedegree of access control between a patient room 700 as illustrated inFIG. 7 , and a common environment 600 as illustrated in FIG. 6 . Here,the system 100 is set up for scanning in an open area 800. In thisexemplary embodiment the upper guard device 500 is configured in thedeployed position while the lower guard device 300 is configured in theundeployed position. This may represent a situation, for example, whereit is inconvenient for medical personnel to provide care and/or operatethe system 100 with the lower guard device 300 deployed. Nonetheless, tomaintain desired access control, the upper guard device 500 is deployedand used in combination with one more cones 802 (and/or other stanchionschains, signs, markers, etc., as appropriate) to delineate an accesscontrolled area. It should be appreciated that the system 100 may beconfigured having any combination of first and second deployable guardsin the undeployed or deployed positions respectively.

Certain configurations of the deployable guard devices as describedherein may be preferred for different modes of operation of the portablemedical imaging device 100. For example, as previously described above,it may be advantageous to configure the upper guard device, 500 or 501,in the deployed position while the lower guard device, 300 or 301,remains in the undeployed position, when the portable medical imagingdevice 100 is in a scanning mode. Such a configuration allows for easieraccess for medical personnel to provide care and/or operate the system100 while the lower guard device is undeployed. In transit, the portablemedical imaging device 100 may pass through an uncontrolled area, suchas a hallway. It may be desirable to configure the portable medicalimaging device with both upper and lower guards deployed while intransit. While in storage, it may be important to provide the lowerguard deployed to protect children from approaching the portable medicalimaging device 100 too closely. In addition to deploying the lower guardwhile in storage, it may be desirable to attach an additional expandableguard that provides a vertical barrier surrounding the portable medicalimaging device 100 from the height of the lower guard to the ground. Thefollowing explanation is provided by way of example and certainconfigurations of the upper and lower guards in the deployed andundeployed positions are not limited in this respect.

Referring now to FIGS. 9 and 10 , there is shown a base 110 of a MRIsystem configured with a deployable guard device 300 having a “hoop”design in the undeployed position and in the deployed position,respectively. In the embodiment depicted, the guard device 300 includesan outer rail 902 having a generally circular configuration, althoughother shapes may be utilized. In the undeployed position shown in FIG. 9, the outer rail 902 has first diameter and may be secured to a supporttrack 904 using a suitable fastening mechanism such as Velcro straps 906for example. The support track 904 may be secured to a base 110 of theMRI system 100 using one or more mounting tabs 914. The support track904 may be formed from a material such as stainless steel and comprise aportion of the MRI system base 110, while the outer rail 902 can beformed from PVC, plastic, or other suitable material(s), for example. Inparticular, the outer rail 902 may be formed from polyethylene.

As particularly shown in FIG. 10 , the guard device 300 further includesan inner rail 908 that is slidingly engaged within the outer rail 902 ina telescoping manner. Thus configured, the extension of the inner rail908 in combination with the outer rail 902 increases the effectivediameter of the guard 300 when in the deployed position. Conversely,because inner rail 908 is disposed substantially entirely within theouter rail 902 in the undeployed position, it is not visible in FIG. 9 .As also shown in FIG. 10 , one or more swing arms 910 may be used tosupport the outer rail 902 as it is moved from the undeployed positionto the deployed position. Each swing arm 910 is attached at first endthereof to the support track 904, and a second end thereof to acorresponding hollow collar 912 through which the outer rail 902 passes.As is the case with the inner rail 908, the swing arms 910 areessentially hidden from view in the undeployed position of FIG. 9 . Thismay be accomplished, for example by fashioning the swing arms 910 in acurved shape such that they conform to the shape of the support track904. FIG. 11 illustrates a more detailed view of the support track 904,swing arm 910 and hollow collar 912, while FIG. 12 illustrates a closeup view of an interior portion of the support track 904, at which thefirst end of the swing arm 910 (not shown in FIG. 12 ) is affixed. Insome embodiments, the one or more swing arms 910 and hollow collars 912may be formed of aluminum and/or any other suitable material(s). In someembodiments, the one or more swing arms 910, hollow collars 912, supporttrack 904, outer rail 902 and inner rail 908 may all be formed from aplastic material, such as polyethylene, for example.

In some embodiments, the deployable guard device 300 having the “hoop”design comprises an inner portion 604 and an outer portion 602, as seenin FIG. 3A. The inner portion 604 may comprise the support track 904, asdescribed herein. The outer portion 602 may comprise the inner rail 908and the outer rail 902, as described herein.

In some embodiments of the technology described herein, the deployableguard device 301 may have a “clover” design. The deployable guard device301 having the “clover” design may be coupled to the base 110 of an MRIsystem. The deployable guard device 301 may comprise first rail portions1008 and second rail portions 1002, as shown in FIGS. 3D-3E. First railportions 1008 and second rail portions 1002 may be formed from amaterial such as aluminum, for example. The second rail portions 1002may have a slotted track 1010 having an inner end 1010A and an outer end1010B. The first rail portions 1008, shown in FIG. 17 , may be coupledwith the second rail portions 1002 to form arcuate sections 1012A-D. Inthe illustrated embodiment, the deployable guard device 301 comprisesfour arcuate sections 1012A-D symmetric with respect to each other, butthe inventors have recognized that any suitable number of arcuatesections may be employed.

A sliding end 1008A of each first rail portion 1008 may be coupled toeach second rail portion 1002 such that the sliding end 1008A of thefirst rail portion 1008 may slide along the slotted track 1010 of thesecond rail portion 1002. For example, the sliding end 1008A of thefirst rail portion 1008 may move between the inner end 1010A and theouter end 1010B of the slotted track 1010 of the second rail portion1002. In this way, the arcuate sections 1012A-D of the deployable guarddevice 301 may be adjusted in length as the sliding end 1008A of thefirst rail portion 1008 slides between inner and outer ends 1010A, 1010Bof the slotted track 1010 of the second rail portion 1002. For example,when the deployable guard device 301 is in the deployed position, thefirst rail portions 1008 may slide to the outer end 1010B of the slottedtrack 1010, thereby lengthening the arcuate sections 1012A-D of thedeployable guard device 301. When the deployable guard device 301 is inthe undeployed position, on the other hand, the sliding end 1008A of thefirst rail portion 1008 may slide to the inner end 1010A of the slottedtrack 1010 of the second rail portion 1002, thereby shortening thelength of the arcuate sections 1012A-D of the deployable guard device301.

The deployable guard device 301 may comprise a support track 904 whichcan be coupled to the base 110 of the MRI system 100 using one or moremounting tabs 914. First rail portions 1008 and second rail portions1002 may be secured to the support track 904 when the deployable guarddevice 301 is in the undeployed position. The deployable guard device301 may further comprise swing arms 910 supporting the first railportions 1008 and the second rail portions 1002 as they are moved fromthe undeployed position to the deployed position. Each swing arm 910 isattached at a first end thereof to the support track 904, and secondends thereof are attached to ends of respective arcuate sections1012A-D. The support track 904 may receive the swing arms 910 such thatthe swing arms 910 are essentially hidden from view in the undeployedposition. This may be accomplished, for example by fashioning the swingarms 910 in a curved shape such that they conform to the shape of thesupport track 904.

In some embodiments, the deployable guard device 301 having the “clover”design comprises an inner portion 608 and an outer portion 606, as seenin FIG. 3D. The inner portion 608 may comprise the support track 904, asdescribed herein. The outer portion 606 may comprise the first railportion 1008 and the second rail portion 1002, as described herein.

In some embodiments, the deployable guard device may have an “inflatableguard” design. The deployable guard device having an “inflatable guard”design may comprise an inflatable ring coupled to the MRI system 100.The inflatable ring may be deflated in an undeployed position, andinflated in a deployed position.

The inventors have recognized that the deployable guard device may bemoved from the undeployed position to the deployed position and viceversa by mechanical or manual means. In some embodiments wherein thedeployable guard device has a “hoop” design, an operator may simplygrasp and pull the outer rail 902 in a radially outward direction,exposing the swing arms 910 and inner rail 908 until the guard device300 reaches its maximum outer diameter. Conversely, the operator may thepush the inner rail 902 in radially inward direction until the swingarms 910 are completely within the support track 904 and the and innerrail 908 is completely within the outer rail 902 (as in FIG. 9 ). Insome embodiments wherein the deployable guard device has a “clover”design, an operator may grasp the first rail portion 1008 and the secondrail portion 1002 and pull them in a radially outward direction, movingthe sliding end 1008A of the first rail portion 1008 from the inner end1010A of the slotted track 1010 to the outer end 1010B of the slottedtrack 1010, until the arcuate sections 1012A-D reach a maximum length.Conversely, the operator may push the first rail portion 1008 and thesecond rail portion 1002 together in a radially inward direction suchthat the sliding end 1008A of the first rail portion 1008 moves from theouter end 1010B of the slotted track 1010 to the inner end 1010A of theslotted track 1010, until the arcuate sections 1012A-D reach a minimumlength.

In some embodiments, the deployable guard device may be expanded (e.g.,to move from the undeployed to a deployed position) or contracted (e.g.,to move from the deployed to the undeployed position) mechanically(e.g., pneumatically and/or hydraulically). For example, in someembodiments, the guard device may be moved from the undeployed positionto the deployed position by providing compressed air that causes outwardexpansion of the inner and outer rails 908, 902 and, conversely theapplication of vacuum pressure to retract the inner and outer rails 908,902. In some embodiments, the guard device 300 may be moved from theundeployed position to the deployed position and vice versapneumatically by one or more pistons (e.g., arranged in the supporttrack 904 of the deployable guard device 300 having a “hoop” design).Moving the deployable guard device between the undeployed position andthe deployed position may comprise either of the techniques describedherein, or a combination of each technique, as the technology is notlimited in this respect. The inventors have further recognized thatthese techniques may be used with a deployable guard device according toany of the embodiments of the technology described herein, such as adeployable guard device having a “hoop” design, a deployable guarddevice having a “clover” design, or a deployable guard having an“inflatable guard” design.

In some embodiments, the operator may mechanically move the deployableguard device 300 between undeployed and deployed positions by pressing abutton. The button may be located anywhere such as on the deployableguard device 300, on the MRI system 100, or on an external device suchas a controller 916 coupled to the deployable guard device 300 and/orthe MRI system 100. In some embodiments, the deployable guard device 300may automatically move between undeployed and deployed positions, forexample, in response to an event. The event may be any number of eventswhich may include, for example, one or more of turning on the MRI system100, turning off the MRI system 100, beginning to perform a scanningoperation, deploying/undeploying a second deployable guard device 500,applying a manual force to the deployable guard device 300, or inresponse to sensing a bystander is beginning to approach the MRI system100.

In some embodiments, the deployable guard device 300 may be implementedin combination with one or more sensors, such as a light or audio signalindicating when a bystander is approaching the deployable guard device.The sensor(s) may serve as a further indication, in addition to thephysical barrier provided by the deployable guard device, that thebystander is approaching a region with higher strength fringe fieldsthat may be dangerous to the bystander if entered.

The inventors have appreciated that there are several advantages toemploying the deployable guard device in accordance with the embodimentsdescribed herein. The deployable guard device according to theembodiments described herein can be configured to remain coupled to theportable medical imaging device 100 during all modes of operation of thedevice 100. For example, the portable medical imaging device 100 may behave a scanning mode, a transit mode, and a storage mode. The deployableguard device according to the above-described embodiments is configuredto be coupled to the deployable guard device and capable of movingbetween deployed and undeployed positions. Therefore, the deployableguard device can easily move with the portable medical imaging device100 between modes of operation without the need to remove or reinstallthe deployable guard device. In addition, the deployable guard deviceaccording to the embodiments described herein may be easy to transport,easy to store, and relatively inexpensive to manufacture.

Although the deployable guard device has been described herein as havinga deployed position and undeployed position, the inventors haveappreciated that in some embodiments, there may be a sequence ofdifferent deployed positions. A deployable guard device having asequence of different deployed positions may be configured to preventencroachment to respective regions of different sizes. For example, thesequence of deployed positions may comprise a first deployed positionsubstantially corresponding to a 10 Gauss line, a second deployedposition substantially corresponding to a 5 Gauss line, and a thirdposition corresponding to a 1 Gauss line. The sequence of differentdeployed positions may be implemented using a deployable guard deviceaccording to any of the embodiments of the technology described herein.

FIGS. 13A-E illustrate views of a deployable guard device 301 having a“clover” design, including views of the guard in deployed and undeployedconfigurations, in accordance with some embodiments of the technologydescribed herein. FIG. 13A illustrates a top view of the deployableguard device 301 in the deployed position. FIG. 13B illustrates across-sectional view of the deployable guard device 301 in theundeployed position. FIG. 13C illustrates a side view of the deployableguard device 301 in the undeployed position. FIG. 13D illustrates a topview of the deployable guard device 301 in the undeployed position. FIG.13E illustrates an isometric view of the deployable guard device 301 inthe undeployed position.

FIGS. 14A-D illustrate views of a support track 904 of deployable guarddevice 301, in accordance with some embodiments of the technologydescribed herein. FIG. 14A illustrates a side view of the support track904 of deployable guard device 301. FIG. 14B illustrates across-sectional view along the line B-B of the support track 904 ofdeployable guard device 301. FIG. 14C illustrates a top view of thesupport track 904 of deployable guard device 301. FIG. 14D illustratesan isometric view of the support track 904 of deployable guard device301.

FIGS. 15A-D illustrate views of a mounting tab 914 of a deployable guarddevice 301. FIG. 15A illustrates an isometric view of the mounting tab914 of deployable guard device 301. FIG. 15B illustrates a side view ofthe mounting tab 914 of deployable guard device 301. FIG. 15Cillustrates a front view of the mounting tab 914 of deployable guarddevice 301. FIG. 15D illustrates a cross-sectional view along the lineC-C of the mounting tab 914 of deployable guard device 301.

FIGS. 16A-C illustrate views of a swing arm 910 of deployable guarddevice 301, in accordance with some embodiments of the technologydescribed herein. FIG. 16A illustrates a front view of the swing arm 910of deployable guard device 301. FIG. 16B illustrates a side view of theswing arm 910 of deployable guard device 301. FIG. 16C illustrates aside view of the swing arm 910 of deployable guard device 301.

FIGS. 17A-B illustrate views of a rail portion 1008 of deployable guarddevice 301, in accordance with some embodiments of the technologydescribed herein. FIG. 17A illustrates a front view of the first railportion 1008 of the deployable guard device 301. FIG. 17B illustrates aside view of the first rail portion 1008 of the deployable guard device301.

FIG. 18A-C illustrate views of another rail portion 1002 of thedeployable guard device 301, in accordance with some embodiments of thetechnology described herein. FIG. 18A illustrates a cross-sectional viewalong the line E-E of the second rail portion 1002 of the deployableguard device 301. FIG. 18B illustrates a front view of the second railportion 1002 of the deployable guard device 301. FIG. 18C illustrates aside view of the second rail portion 1002 of the deployable guard device301.

FIGS. 19A-F illustrate views of a deployable guard device 300 having a“hoop” design, in accordance with some embodiments of the technologydescribed herein. FIG. 19A illustrates a front view of the deployableguard device 300 in the deployed position. FIG. 19B illustrates a frontview of the deployable guard device 300 in the undeployed position. FIG.19C illustrates an isometric view of the deployable guard device 300 inthe undeployed position. FIG. 19D illustrates a cross-sectional viewalong the line B-B of the deployable guard device 300 in the undeployedposition. FIG. 19E illustrates a cross-sectional view along the line A-Aof the deployable guard device 300 in the undeployed position. FIG. 19Fillustrates a side view of the deployable guard device 300 in theundeployed position.

FIGS. 20A-D illustrate views a support track 904 of the deployable guarddevice 300, in accordance with some embodiments of the technologydescribed herein. FIG. 20A illustrates a cross-sectional view along theline C-C of the support track 904 of the deployable guard device 300.FIG. 20B illustrates a side view of the support track 904 of thedeployable guard device 300. FIG. 20C illustrates a front view of thesupport track 904 of the deployable guard device 300. FIG. 20Dillustrates an isometric view of the support track 904 of the deployableguard device 300.

FIGS. 21A-E illustrate views of a mounting tab 914 of a deployable guarddevice 300, in accordance with some embodiments of the technologydescribed herein. FIG. 21A illustrates a side view of the mounting tab914 of the deployable guard device 300. FIG. 21B illustrates a frontview of the mounting tab 914 of the deployable guard device 300. FIG.21C illustrates a cross-sectional view along the line D-D of themounting tab 914 of the deployable guard device 300. FIG. 21Dillustrates a bottom view of the mounting tab 914 of the deployableguard device 300. FIG. 21E illustrates an isometric view of the mountingtab 914 of the deployable guard device 300.

FIGS. 22A-C illustrate views of a swing arm 910 of a deployable guarddevice 300, in accordance with some embodiments of the technologydescribed herein. FIG. 22A illustrates a side view of the swing arm 910of the deployable guard device 300. FIG. 22B illustrates across-sectional view along the line E-E of the swing arm 910 of thedeployable guard device 300. FIG. 22C illustrates a front view of theswing arm 910 of the deployable guard device 300.

FIGS. 23A-D illustrate views of a hinge having ball detents of a supporttrack of a deployable guard device 300, in accordance with someembodiments of the technology described herein. FIG. 23A illustrates across-sectional view along the line F-F of the hinge having ball detentsof the support track of the deployable guard device 300. FIG. 23Billustrates a side view of the hinge having ball detents of the supporttrack of the deployable guard device 300. FIG. 23C illustrates anisometric view of the hinge having ball detents of the support track ofthe deployable guard device 300. FIG. 23D illustrates a front view ofthe hinge having ball detents of the support track of the deployableguard device 300. FIG. 23E illustrates a rear view of the hinge havingball detents of the support track of the deployable guard device 300.FIG. 23F illustrates a top view of the hinge having ball detents of thesupport track of the deployable guard device 300. FIG. 23G illustrates asecond side view of the hinge having ball detents of the support trackof the deployable guard device 300. FIG. 23H illustrates across-sectional view along the line G-G of the hinge having ball detentsof the support track of the deployable guard device 300.

FIGS. 24A-C illustrate views of inner and outer rails 908, 902 of adeployable guard device 300, in accordance with some embodiments of thetechnology described herein. FIG. 24A illustrates a top view of innerand outer rails 908, 902 of the deployable guard device 300. FIG. 24Billustrates a side view of inner and outer rails 908, 902 of thedeployable guard device 300. FIG. 24C illustrates a bottom view 908, 902of inner and outer rails of the deployable guard device 300.

The above-described embodiments can be implemented in any of numerousways. For example, the embodiments may be implemented using hardware,software or a combination thereof. When implemented in software, thesoftware code can be executed on any suitable processor (e.g., amicroprocessor) or collection of processors, whether provided in asingle computing device or distributed among multiple computing devices.It should be appreciated that any component or collection of componentsthat perform the functions described above can be generically consideredas one or more controllers that control the above-discussed functions.The one or more controllers can be implemented in numerous ways, such aswith dedicated hardware, or with general purpose hardware (e.g., one ormore processors) that is programmed using microcode or software toperform the functions recited above.

In this respect, it should be appreciated that one implementation of theembodiments described herein comprises at least one computer-readablestorage medium (e.g., RAM, ROM, EEPROM, flash memory or other memorytechnology, CD-ROM, digital versatile disks (DVD) or other optical diskstorage, magnetic cassettes, magnetic tape, magnetic disk storage orother magnetic storage devices, or other tangible, non-transitorycomputer-readable storage medium) encoded with a computer program (i.e.,a plurality of executable instructions) that, when executed on one ormore processors, performs the above-discussed functions of one or moreembodiments. The computer-readable medium may be transportable such thatthe program stored thereon can be loaded onto any computing device toimplement aspects of the techniques discussed herein. In addition, itshould be appreciated that the reference to a computer program which,when executed, performs any of the above-discussed functions, is notlimited to an application program running on a host computer. Rather,the terms computer program and software are used herein in a genericsense to reference any type of computer code (e.g., applicationsoftware, firmware, microcode, or any other form of computerinstruction) that can be employed to program one or more processors toimplement aspects of the techniques discussed herein.

Various aspects of the present invention may be used alone, incombination, or in a variety of arrangements not specifically discussedin the embodiments described in the foregoing and is therefore notlimited in its application to the details and arrangement of componentsset forth in the foregoing description or illustrated in the drawings.For example, aspects described in one embodiment may be combined in anymanner with aspects described in other embodiments.

Also, the invention may be embodied as a method, of which an example hasbeen provided. The acts performed as part of the method may be orderedin any suitable way. Accordingly, embodiments may be constructed inwhich acts are performed in an order different than illustrated, whichmay include performing some acts simultaneously, even though shown assequential acts in illustrative embodiments.

Use of ordinal terms such as “first,” “second,” “third,” etc., in theclaims to modify a claim element does not by itself connote anypriority, precedence, or order of one claim element over another or thetemporal order in which acts of a method are performed, but are usedmerely as labels to distinguish one claim element having a certain namefrom another element having a same name (but for use of the ordinalterm) to distinguish the claim elements.

Also, the phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having,” “containing,” “involving,” andvariations thereof herein, is meant to encompass the items listedthereafter and equivalents thereof as well as additional items.

In the claims, as well as in the specification above, all transitionalphrases such as “comprising,” “including,” “carrying,” “having,”“containing,” “involving,” “holding,” “composed of,” and the like are tobe understood to be open-ended, i.e., to mean including but not limitedto. Only the transitional phrases “consisting of” and “consistingessentially of” shall be closed or semi-closed transitional phrases,respectively.

The terms “approximately”, “substantially,” and “about” may be used tomean within ±20% of a target value in some embodiments, within ±10% of atarget value in some embodiments, within ±5% of a target value in someembodiments, and within ±2% of a target value in some embodiments. Theterms “approximately” and “about” may include the target value.

What is claimed is:
 1. An apparatus comprising: a deployable guarddevice configured to be coupled to a portable magnetic resonance imagingdevice and, when deployed, inhibit encroachment within a physicalboundary with respect to the portable magnetic resonance imaging device,wherein: when in an undeployed position, the deployable guard devicedefines a first inner region having a first area, when in a deployedposition, the deployable guard device defines a second inner regionhaving a second area larger than the first area, and when in thedeployed position, the deployable guard device extends radially furtherfrom an imaging region of the portable magnetic resonance imaging devicethan when the deployable guard device is in the undeployed position. 2.The apparatus of claim 1, wherein deployable guard device comprises anextendible rail having a first diameter in the undeployed position, anda second diameter in the deployed position, and the second diameter isgreater than the first diameter.
 3. The apparatus of claim 2, whereinthe extendible rail further comprises: an outer rail; and an inner railslidingly engaged within the outer rail in a telescoping manner, suchthat in the undeployed position, the inner rail is disposedsubstantially entirely within the outer rail, and, in the deployedposition, at least a portion of the inner rail is exposed.
 4. Theapparatus of claim 3, wherein the deployable guard device furthercomprises: a support track, configured to be secured to the portablemagnetic resonance imaging device; and one or more swing arms, connectedat a first end thereof to the support track and connected to the outerrail at a second end thereof.
 5. The apparatus of claim 4, wherein thesecond end of the one or more swing arms is extended in a radiallyoutward direction from the support track in the deployed position. 6.The apparatus of claim 1, wherein the physical boundary corresponds to avolume that encompasses a region having a defined magnetic fieldstrength within a range from about 1 Gauss to about 30 Gauss.
 7. Theapparatus of claim 1, wherein the physical boundary corresponds to avolume that encompasses a region having a defined magnetic fieldstrength within a range from about 5 Gauss to about 20 Gauss.
 8. Theapparatus of claim 1, wherein the deployable guard device issubstantially radially symmetrical.
 9. The apparatus of claim 1, whereinthe deployable guard device further comprises: multiple arcuatesections, including a first arcuate section, wherein when the deployableguard device is in the deployed position, a first point on the firstarcuate section is at a first distance from an isocenter of thedeployable guard device, and a second point on the first arcuate sectionis at a second distance from the isocenter, and wherein the first andsecond distances are different from each other.
 10. The apparatus ofclaim 9, wherein the multiple arcuate sections each comprise a firstrail and a second rail slidingly engaged with the first rail.
 11. Theapparatus of claim 10, wherein the first rail comprises a slotted trackconfigured to receive the second rail.
 12. The apparatus of claim 1,further comprising at least one light that, when the deployable guarddevice is in the deployed position, provides an indication of thepresence of a magnetic field.
 13. An apparatus comprising: a deployableguard device configured to be coupled to a portable magnetic resonanceimaging device, the deployable guard device further configured to, whendeployed, demarcate a boundary within which a magnetic field strength ofa magnetic field generated by the portable magnetic resonance imagingdevice equals or exceeds a given threshold, wherein: when in a deployedposition, the deployable guard device extends radially further from animaging region of the portable magnetic resonance imaging device thanwhen the deployable guard device is in an undeployed position; and thedeployable guard device is configured to automatically move between theundeployed position and the deployed position in response to applicationof a force on the deployable guard device.
 14. The apparatus of claim13, wherein the deployable guard device comprises an extendible railhaving a first diameter in the undeployed position, and a seconddiameter in the deployed position, and the second diameter is greaterthan the first diameter.
 15. The apparatus of claim 13, wherein thephysical boundary corresponds to a volume that encompasses a regionhaving a defined magnetic field strength within a range from about 1Gauss to about 30 Gauss.
 16. The apparatus of claim 13, wherein thedeployable guard device is substantially radially symmetrical.
 17. Theapparatus of claim 13, wherein the deployable guard device furthercomprises: multiple arcuate sections, including a first arcuate section,wherein when the deployable guard device is in the deployed position, afirst point on the first arcuate section is at a first distance from anisocenter of the deployable guard device, and a second point on thefirst arcuate section is at a second distance from the isocenter, andwherein the first and second distances are different from each other.18. The apparatus of claim 13, further comprising at least one lightthat, when the deployable guard device is in the deployed position,provides an indication of the presence of a high-strength magneticfield.
 19. The apparatus of claim 13, wherein the force comprises amanual force.
 20. A method for using a deployable guard device coupledto a portable magnetic resonance imaging device, the deployable guarddevice further configured to, when deployed, demarcate a boundary withinwhich a magnetic field strength of a magnetic field generated by theportable magnetic resonance imaging device equals or exceeds a giventhreshold, the method comprising: applying a first force to thedeployable guard device, wherein the first force causes the deployableguard device to automatically move from an undeployed position to adeployed position, wherein: when in the deployed position, thedeployable guard device extends radially further from an imaging regionof the portable magnetic resonance imaging device than when thedeployable guard device is in the undeployed position; and applying asecond force to the deployable guard device, wherein the second forcecauses the deployable guard device to automatically move from thedeployed position to the undeployed position.
 21. The method of claim20, further comprising, subsequent to applying the second force to thedeployable guard device, imaging, using the portable magnetic resonanceimaging device.
 22. The method of claim 20, wherein the first forcecomprises a first manual force and the second force comprises a secondmanual force.